/Engine/Source/Runtime/Engine/Classes/Particles/ParticleLODLevel.h
Append all used materials to the material list.
void GetUsedMaterials ( [TArray](API\Runtime\Core\Containers\TArray)< [UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * > & OutMaterials, const [TArray](API\Runtime\Core\Containers\TArray)< struct [FNamedEmitterMaterial](API\Runtime\Engine\Particles\FNamedEmitterMaterial) > & NamedMaterialSlots, const [TArray](API\Runtime\Core\Containers\TArray)< [UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * > & EmitterMaterials ) const